2003/12/12 by L. N. Bulaevskiǐ, L. Bulaevskii, M. Hruška +6 · 1 citation
Computer Science · Physics and Astronomy · #Atomic and Subatomic Physics Research #Quantum Information and Cryptography #Quantum and electron transport phenomena #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.92.177001
published as Phys. Rev. Lett. 92, 177001 (2004) · 4 pages, 1 figure; average value of spin z operator changed to eigenvalue S_z
arxiv created 2003/12/12 · openalex publication_date 2004/04/27 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
We consider a single localized spin-1/2 between the singlet superconducting leads of a Josephson junction (e.g., a superconducting STM). For the spin subject to a dc magnetic field B parallel z, we study the spin dynamics and the possibility to measure the spin state via transport through the junction embedded in a dissipative circuit. Turning on the tunneling or a voltage bias induces oscillations of the Josephson current, with an amplitude sensitive to the initial value of the z component of the spin, S(z)=+/-1/2. At low temperatures, when effects of quasiparticles are negligible, this procedure realizes a quantum nondemolition measurement of S(z).